People often irrigate their lawns with automatic irrigation systems that operate on a fixed schedule, where the user sets the run time, minutes, and days for each station, and the controller provides the same irrigation run time(s) regardless of the season or weather. Such controllers require the user to make adjustments to the fixed schedule to account for seasonal variations. Some of these controllers incorporate sensors that can detect rain fall, and can suspend irrigation for one or several days, but ultimately the controller returns to the same fixed schedule entered by the user. Adjustment to the fixed schedule are made based upon the user's perception of the irrigation needs, which in turn can be based upon the appearance of the yard or other factors such as seasonal changes. While fixed schedule controllers satisfy the basic need of many user's by providing irrigation to each station, without adjustment for seasonal and daily variations the fixed schedule that is correct for one day might be either too much or too little irrigation for other days. An ideal irrigation controller should make adjustments to the irrigation run times to account for seasonal and/or daily environmental variations, as well as provide for automatic skipping of watering when it rains or when irrigation run times would be too short.
Some users make two or more fixed schedule changes each year. They usually make the first change in the spring when they notice a portion of the yard is becoming brown due to a lack of irrigation. The second change is often made in the fall when the user notices an excessive amount of irrigation. The changes made by the user can be entered by changing the days the system runs, or changing the duration(s) for each station. In general a reduction in the total irrigation time allows for a reduction in the irrigation being applied. While an increase in total irrigation time allows for an increase in the irrigation being applied. Numerous systems available today allow for a manual season adjustment where the user can increase or decrease the irrigation time for the stations by entering a single adjustment. Controllers with this feature however are still dependent upon human interaction to make the seasonal adjustment. This is potentially problematic because the average user may have insufficient knowledge to make an accurate adjustment, and the adjustments made for one day may not be accurate for another day. In addition, making changes to the seasonal adjustment does not allow the controller to skip days when the irrigation run time is too short to ensure deep irrigation.
Another popular method of altering irrigation in modern irrigation controllers incorporates a rain sensor shut off. When the sensor detects rain it makes the controller suspend irrigation until the rain has stopped. In other instances the rain shut off is manual, and often includes a rain delay button to allow for suspension of irrigation when rain is present or immanent. See U.S. Pat. Nos. 5,381,331 and 5,272,620. While this feature allows the user to suspend irrigation, it does not provide automatic suspension or adjustment for the rainy season.
More sophisticated controllers such as that disclosed in U.S. Pat. No. 4,646,224 automatically determine the number of cycles and length of time of that each irrigation is to be applied. However, such controllers require the operator to provide detailed data concerning desired sprinkling days, soil type, the type of sprinkler for each zone, and so forth. Moreover, while they allow for more accurate irrigation times, they are complicated to program, and do not automatically adjust for weather or seasonal variation.
Some controllers incorporate sensors that can detect moisture in the soil, suspend irrigation while the sensor detects moisture above a given threshold. Controllers of this type help to reduce over irrigating, but the placement of the sensor(s) are critical to correct irrigation. Another undesirable effect of using soil moisture controller's is that once they begin irrigation they will continue to irrigate for the same fixed duration.
Other controllers take measurements from numerous external sensors, such as humidity, precipitation, temperature, soil moisture, and wind to calculate the landscape irrigation use. These systems offer the best irrigation savings, but the cost and maintenance of the sensors can be extremely high.
Still other controllers incorporate pagers to receive an evapotranspiration (ETo) factor. The controllers of this type can receive multiple ETo factors for numerous zones. They use identifiers to determine the ETo information of their location and then calculate the run time for each station. Known controllers of this type have no sensors, but receive ETo input from a local or distal signal source. Disclosures of this type are U.S. Pat. No. 4,962,522, issued October 1990, and U.S. Pat. No. 5,208,855, issued May 1993, both to Marian, and each of which is incorporated by reference herein in its totality. The large quantity of data that can be received and interpreted makes ETo controllers complicated to use, and even systems touting automatic adjustment of irrigation flow still require relatively complicated input. Systems discussed in the U.S. Pat. No. 5,208,855, for example, receive the signal, and update an interval used for preset irrigation control timings rather than determine an entirely new irrigation schedule. Systems discussed in U.S. Pat. No. 5,444,611 to Woytowitz et al. (August, 1995) are said to automatically calculate and execute a new schedule, but the new schedule is based upon the season, and the ET value is from a weather station that may not be local to the controller.
The trend towards increasingly sophisticated controllers is accompanied by a trend towards simpler more intuitive user interface's with and little or no user intervention to account for weather or seasonal variation. Nevertheless, known controllers fall short of providing improved irrigation savings and minimizing the need for user interface, and the available options for user interface remain a relatively complex combination of buttons, dials and alphanumerical displays Summary of the Invention.
Methods and apparatus are provided herein that allow extremely simple user interface and control over sophisticated irrigation controller output. In one aspect of a particular class of embodiments, the operator enters the time, date, and the duration for each station. From that point on the controller uses historical information to determine the amount of irrigation to be applied each day. Such automatic scheduling determination may be further improved by use of a modem or other communication device that can provide local periodic ETo information. The automatic scheduling determination may be still further improved by use of one or more environmental sensors such as a temperature sensors or other measurement mechanism that can use the specific location information combined with or without geographic zone information to determine daily ETo irrigation requirements. In yet another aspect of the preferred embodiments, the owner may allow the controller to accumulate unapplied irrigation until a sufficient quantity has accumulated that will ensure deep irrigation. In yet another aspect of the preferred embodiments, the controller can provide feedback on irrigation savings. In yet another aspect of the preferred embodiments, the controller saves the current date in memory such that if a long-term loss of power occurs, seasonal error will be minimized. In yet another aspect of the preferred embodiments, the controller automatically accounts for additional ETo that occurs following irrigation.
Various objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description of preferred embodiments of the invention, along with the accompanying drawings in which like numerals represent like components.